The present application relates to an anti-glare film, a method of manufacturing the same, and a display device. More particularly, the present application relates to an anti-glare film used for a display surface of display devices such as liquid crystal display devices.
A technique of providing an anti-glare film on the display surface side has been adopted to display devices such as liquid crystal display devices, aiming at diffusing light on the film, to thereby impart anti-glare properties, or to reduce glare of external light due to reflection on the surface. A known anti-glare film is to impart anti-glare properties by providing fine irregularities formed on the surface.
FIG. 8 shows a configuration of a known anti-glare film 101. The anti-glare film 101 includes a base 111, and an anti-glare layer 112 provided on the base 111. The anti-glare layer 112 contains particles 113, wherein projection of the particles 113 out from the surface of the anti-glare layer 112 contributes to form fine irregularities on the surface. The anti-glare film 101 is formed by applying a coating composition containing particles 113 such as irregular-shaped silica particles or fine organic particles on the base 111, and the coating is then allowed to dry. In the anti-glare film having the above configuration, light incident upon the anti-glare layer 112 is scattered by the particles 113 projected out from the anti-glare layer 112, and whereby glare ascribable to reflection on the surface may be reduced.
The fine irregularities have been investigated, aiming at more effectively imparting the anti-glare properties to the anti-glare film. For example, for the purpose of preventing glare, Japanese Patent No. 3821956 (hereinafter referred to as “Patent Document 1”) proposes selection of the center-line mean roughness and mean top-bottom distance of the fine irregularities to 0.08 to 0.5 micrometers, and 20 to 80 micrometers, respectively. Aiming at achieving a desirable level of anti-glare properties, Japanese Patent No. 3374299 (hereinafter referred to as “Patent Document 2”) proposes provision of coarse irregularities and fine irregularities, while adjusting the center-line mean roughness Ra of the surface having these irregularities provided thereon to 0.1 to 1.0 μm, mean distance Sm to 20 to 130 μm, and further adjusting the center-line mean roughness Ra of the coarse irregularity to 0.5 to 1.5 μm, mean distance Sm to 100 to 300 μm, the center-line mean roughness Ra of the fine irregularity to 0.05 to 0.5 μm, and mean distance Sm to 20 to 70 μm.